General Public

Unfortunately, Kofiko is not available for the general public.

Students

Our original idea was to allow the students the opportunity to program their own code for stimulus presentation.

This has worked out nicely last year when we did human scans. However, this year we will be doing only monkey scans. This means that programming the stimuli is a little bit more tricky, because

it involves giving juice rewards, keeping track of eye position, etc.

To circumvent many of these issues, we have decided to make things easier for you and use an already existing platform that Shay has developed for presenting stimuli for monkeys (a.k.a “KOFIKO”).

This platform will take care of all the “irrelevant” details mentioned above and will help you focus on the more important stuff.

 

The block design paradigm in Kofiko is quite generic. It can display images and movies at any specified size. It takes care of all timing issues.

At the moment, it is set to present block of images/movies. The duration of each block is the same.

To interface with the block design paradigm in Kofiko, you will need to prepare several things:

1. Stimuli (images / movies)

Any image type is acceptable (jpg/bmp/gif/….). Note that due to memory requirements, the system cannot load more than 2GB of image data.

Take this into consideration when you prepare the images, with special care to their size (i.e., don’t make images that are 2000×3000 pixels…. )

Movies are acceptable, however, they must be in quicktime format, and their bandwidth should be low.

Again, if you exceed frame size for movies, you will encounter jitter and delay issues when presenting these images.

 

2. Stimuli List File

This is a simple text file that contains a list of all your stimuli.

Each line starts with a unique number that identifies the stimulus.

The images/movies can be stored in sub-folders.

Here is an example how a file should look like:

—————————————-

 

1 Bodies\\body1.tif
2 Bodies\\body10.tif
3 Bodies\\body11.tif
4 Bodies\\body12.tif
5 Bodies\\body13.tif
6 Faces\\Image1.jpg
7 Faces\\Image1.jpg
8 Faces\\Movie1.mov

—————————————-

 

 

3. Block List File

This is also a simple text file.

It has the following structure:

—————————————————

 

Block1: Bodies
1
2
3
4
5
Block2: Face_Images
6
7
Block3: Face_Movies
8
Block4: Mixed_Images
1
2
5
6
—————————————————

This, for example, defines four blocks. The images within a block will be displayed one after the other, in a cycle, until the block duration is over.

 

 

4. Block Order File

This is another text file which determines the order in which blocks will be presented.
For example:
————————————————–
Bodies
Face_Images
Bodies
Mixed_Images
————————————————–

5. The “Experiment” File

This is another text file that just contains the names of the three previous files, in this order (for example):

 

—————————————————-
Stimuli.txt
BlockList.txt
BlockOrder.txt
—————————————————-

 

Testing your stimuli

Download this file [Kofiko_BlockDesign_Standalone.zip], extract its content somewhere, open matlab (32 bit), make sure PTB is installed, change directory to where you extracted the contents, and then run “BlockDesign.m”.

Download this experiment [Cns184_BlockDesignExample.rar], extract its content somewhere and click on “Load Experiment”. Then load “Experiment.txt”.

Make sure the PTB screen is correct, and then click “Start”. Then, click on “1” to simulate a scanner trigger. This should start showing the images.